The purpose of this is for changing the mixture of a liquid used in electronic cigarettes. I will use an example to describe what I'm asking.

Current liquid mixture:

5ml is the total volume of the liquid.

It has a nicotine strength of 12mg. This means 12mg per ml. That is a total of 60mg of nicotine within the 5ml.

When mixing the liquid I use a Nicotine base of 37.5mg per ml. The other ingredients used to obtain the total 5ml are unimportant for the scope of this thread.

Basically it required that 1.6ml of the example nicotine base is part of the 5ml total liquid to acquire 12mg nicotine strength. (60mg divided by 37.5mg)

WHAT I AM TRYING TO ACHIEVE: I want to up the strength to 18mg of nicotine.

If I would have made the liquid 18mg to begin with I would have used 2.4ml of nicotine base. Which is a 0.8 increase. Resulting in 18mg strength within 5ml of liquid.

Of course if add 0.8ml of nicotine base to the already mix liquid I will now have a total of 5.8ml of liquid. This gives me 90mg of liquid, but with now a 5.8ml volume which is only approx 15.5mg of nicotine strenght. I can do the same crude calculations over and over to an X number of times until I get close to 18mg of nicotine strength. When I do it over and over, adjusting more and more, little by little in the math I eventually figure out what I need. Adding somewhere between 1.5 to 1.6ml of my nicotine base results in what I need to add.

But I want to know if an equation is possible to skip all the trial and error or should I say adjust and then re-adjust.

I'm not doing all this to help me change one stupid mixture. This would help me accomplish a small but important percentage of what is needed to help a community of e-cigarette users through use of a free software available to them to help them change mixtures when their original mixture doesnt give the result they need. Sometimes they find out after testing their liquid that their nicotine, mixture of ingredients, or flavors are not what they hoped for.

Variations from the example. Basically I hope for an equation that assumes that: the total volume may not always be 5ml. The intial nicotine strength may not always be 12mg per ml. The target nicotine strength may not always be 18mg per ml. The nicotine base may not always be 37.5mg per ml. Basically there are no constants.

This is my first post here so I really don't know what to expect from this forum. I appreciate any insight to the conundrum I have.